When it comes to NATO's armored power, it isn't Germany, France, or the United Kingdom that are leading the charge. Instead, Eastern members like Poland and Turkey field some of the largest tank fleets in the Alliance. Their tank arsenals make more sense in the context that these countries are geographically located closer to potential flashpoints. However, the United States has a fairly impressive arsenal of its own tanks within NATO.
In September 1916, the first tank secretly made its way onto the fields of the Battle of Somme. The British had developed the technology and were ready to reveal it on the trenched and barbed wire battlefields of World War I. At the time, they did not prove to have the best track record, breaking down and unreliable, but the psychological effect the machines had on the German soldiers they were fighting was well worth the trouble.